The Dodge Challenger Message Board

hi everyone
is a 340 cast crank stronger than a 318? with all the 318 build ups lately
how much hp can they take?

As you probably know the 340 and 318 cranks are the same and interchange.

However the 340 was always a forged crank. I will have to look up what the 318 crank was but even if it is cast I would not worry about it. A 318 is never going to make more power than the cast crank will take.

72/73 340's have cast cranks also most 318 except maybee some early heavy trucks. i guess my question is will a 318 cast crank hold up in a 340 build around 400hp / 310hp at the wheels?
thanks

I beg your pardon Sir! You are right.

Yes now I look in a book I see the 340 crank was forged up to 1972 and cast from 1973 although I bet there was some overlap on the dates.

I don't know how much power a 318 or 340 cast crank will take but i would bet it is a lot more than 400hp. More like 500-600 I would guess.

RPMs are the limiting factor. If you want an engine that makes its power at 6000-8000 rpm you need to look at a better (lighter) crank and con rod.

thanks for your reply. i never considerd high rpm as a factor

When I redid my 73 3forty Direct Connection recomended shot peening my cast crank. Since the motor did'nt have a lot of miles, and I was'nt planning for a lot more horsepower, I decided to not turn the crank of shot peen it. Shot peening may be an option for you though.